I'm in the process of laying the bathroom floor and it's great! It alerts me to the slightest slip, even a slip I can't feel with my fingers. Also quickly indicates if a tile is not level in any direction. I brought this up as other tools I already have could do the job, but I think it's money well spent. It's much faster and more convenient. I wouldn't tile the floor without it. Combine it with a longer spirit level to ensure your floor stays level and straight over long distances. Bending large tiles (12x24) can reset this level, but moving it to other parts of the tile will quickly alert you to such a problem. I like it!